This day-after-Thanksgiving, when many Americans are enjoying a day off and several others are at work goofing around on OSNews, we decided to ask you: what's your "killer app?" What's the one app you can't live without? Sound off in the comments - one app only!

performance and the gui builder are the two things that come to mind. IMHO VS is a really good IDE, but you need additional plugins to make it truly a killer app, like JetBrains ReSharper or DevExpress CodeRush